631 research outputs found
Self-scheduling of wind-thermal systems using a stochastic MILP approach
In this work a stochastic (Stoc) mixed-integer linear programming (MILP) approach for the coordinated trading of a price-taker thermal (Ther) and wind power (WP) producer taking part in a day-ahead market (DAM) electricity market (EMar) is presented. Uncertainty (Uncer) on electricity price (EPr) and WP is considered through established scenarios. Thermal units (TU) are modelled by variable costs, start-up (ST-UP) technical operating constraints and costs, such as: forbidden operating zones, minimum (Min) up/down time limits and ramp up/down limits. The goal is to obtain the optimal bidding strategy (OBS) and the maximization of profit (MPro). The wind-Ther coordinated configuration (CoConf) is modelled and compared with the unCoConf. The CoConf and unCoConf are compared and relevant conclusions are drawn from a case study
Schedule of Thermal Units with Emissions in a Spot Electricity Market
Part 13: Energy GenerationInternational audienceA bi-objective optimization approach is presented for solving a generation company short-term thermal schedule problem with a few units, considering the goodness of being schedule, but with emission concern. The startup and shutdown for each unit throughout the time horizon is derived from Pareto-optimal solutions, using a method merging dynamic programming and nonlinear programming to provide schedule of the units. A case study is presented to prove the effectiveness of the approach
Ligand-induced reactivity of β-diketiminate magnesium complexes for regioselective functionalization of fluoroarenes via C-H or C-F bond activations
Using β-diketiminate Mg(II) complexes containing either alkyl, aryl or amide groups, the regioselective functionalization of a wide range of fluoroarenes is accomplished but in uniquely different ways. Overcoming common limitations of traditional s-block bases, kinetically activated [(DippNacnac)Mg(TMP)] (1) deprotonates these molecules at room temperature, trapping sensitive fluoroaryl anions that can then engage in Negishi cross-coupling; whereas [(DippNacnac)Mg(R)THF] (R = nBu, Ph, benzofuryl) have proved to be effective reagents for CâF bond alkylation/arylation via pyridine directed CâF bond cleavage
Allosteric Conversation in the Androgen Receptor Ligand-Binding Domain Surfaces
Androgen receptor (AR) is a major therapeutic target that plays pivotal roles in prostate cancer (PCa) and androgen insensitivity syndromes. Wepreviously proposed that compounds recruited to ligand-binding domain (LBD) surfaces could regulate AR activity in hormone-refractory PCa and discovered several surface modulators of AR function. Surprisingly, the most effective compounds bound preferentially to a surface of unknown function [binding function 3 (BF-3)] instead of the coactivator-binding site [activation function 2 (AF-2)]. Different BF-3 mutations have been identified in PCa or androgen insensitivity syndrome patients, and they can strongly affect AR activity. Further, comparison of AR x-ray structures with and without bound ligands at BF-3 and AF-2 showed structural coupling between both pockets. Here, we combine experimental evidence and molecular dynamic simulations to investigate whether BF-3 mutations affect AR LBD function and dynamics possibly via allosteric conversation between surface sites. Our data indicate that AF-2 conformation is indeed closely coupled to BF-3 and provide mechanistic proof of their structural interconnection. BF-3 mutations may function as allosteric elicitors, probably shifting the AR LBD conformational ensemble toward conformations that alter AF-2 propensity to reorganize into subpockets that accommodate N-terminal domain and coactivator peptides. The induced conformation may result in either increased or decreased AR activity. Activating BF-3 mutations also favor the formation of another pocket (BF-4) in the vicinity of AF-2 and BF-3, which we also previously identified as a hot spot for a small compound. We discuss the possibility that BF-3 may be a protein-docking site that binds to the N-terminal domain and corepressors. AR surface sites are attractive pharmacological targets to develop allosteric modulators that might be alternative lead compounds for drug design. Š 2012 by The Endocrie Society
Magnetic Catalysis in AdS4
We study the formation of fermion condensates in Anti de Sitter space. In
particular, we describe a novel version of magnetic catalysis that arises for
fermions in asymptotically AdS4 geometries which cap off in the infra-red with
a hard wall. We show that the presence of a magnetic field induces a fermion
condensate in the bulk that spontaneously breaks CP symmetry. From the
perspective of the dual boundary theory, this corresponds to a strongly coupled
version of magnetic catalysis in d=2+1.Comment: 22 pages, 4 figures. v2: References added, factors of 2 corrected,
extra comments added in appendix. v3: extra comments about fermion modes in a
hard wall background. v4: A final factor of
Investigating the transformations of polyoxoanions using mass spectrometry and molecular dynamics
The reactions of [Îł-SiW10O36]8â represent one of the most important synthetic gateways into a vast array of polyoxotungstate chemistry. Herein, we set about exploring the transformation of the lacunary polyoxoanion [β2-SiW11O39]8â into [Îł-SiW10O36]8â using high-resolution electrospray mass spectrometry, density functional theory, and molecular dynamics. We show that the reaction proceeds through an unexpected {SiW9} precursor capable of undertaking a direct β â Îł isomerization via a rotational transformation. The remarkably low-energy transition state of this transformation could be identified through theoretical calculations. Moreover, we explore the significant role of the countercations for the first time in such studies. This combination of experimental and the theoretical studies can now be used to understand the complex chemical transformations of oxoanions, leading to the design of reactivity by structural control
Analysis of Emerging Reputation and Funding Mechanisms in the Context of Open Science 2.0
This report covers the outcomes of two studies funded by JRC IPTS to explore emerging drivers for Open Science 2.0. In general, Open Science 2.0 is associated with themes such as open access to scientific outputs, open data, citizen science and open peer evaluation systems. This study, however, focused on less explored themes, namely on alternative funding mechanisms for scientific research and on emerging reputation mechanisms for scholars resulting from Web 2.0 platforms and applications. It has been demonstrated that both are providing significant new opportunities for researchers to disseminate, share, explore and collaborate with other researchers, but it remains to be seen whether they will be able to bring about more disruptive change in how science and research systems function in the future. They could well do so, especially if related changes being considered by the European Commission on âScience 2.0: Science in Transitionâ are taken into account.JRC.J.3-Information Societ
Magnesium-mediated arylation of amines via C-F bond activation of fluoroarenes
A series of new Mg(II) amides featuring a bulky β-diketiminate backstop ligand, has been synthesised. These complexes are demonstrated to be excellent sources of nucleophilic amides that can participate in rapid CâF activation of several fluoroarenes at room temperature or using microwave assistance, leading to the installment of synthetically important CâN bonds via nucleophilic substitution
Bio4gas : evaluation and analysis of wastewater treatment facilities in the scope of biogas production maximization and energy production optimization
The present work presents some of the results of five reports developed in the scope of optimization feasibility studies carried out at 6 small- and medium-sized wastewater treatment plants (WWTP) in Portugal. These 6 WWTP are operated by five companies that belong to the Ăguas de Portugal holding. The objective of the studies was twofold: to
assess to which extent the production of biogas could be increased by means of
operational modifications and/or by the implementation of co-digestion regimes; and also
to simulate different scenarios for feed-in tariff of electricity taking in account energy
prices calculated based upon the DL n.Âş 225/2007 of 11th May. In this way, several codigestion
scenarios were defined based upon standard available organic residues. The
results obtained showed that the implementation of co-digestion regimes represent a
significative potential to increase the production of biogas, in some cases, over 600%.
Even though, it was concluded that in some cases the costs of introducing new regimes
of energy management were not supported by the increase of energy production, so a
scale factor is associated to the revenues. This study contributed to the establishment of
specific needs in terms of information management (digester operation, energy
production/consumption, strategy for optimisation)
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